Drill string flow control valves and methods

Abstract

Drill string flow control valves and more particularly, drill string flow control valves for prevention of u-tubing of fluid flow in drill strings are provided. Drill string flow control valves may comprise a valve housing, a valve sleeve axially movable within a valve housing from a closed position to an open position, a biasing mechanism for biasing the valve sleeve into the closed position, and a plurality of pressure ports for allowing a differential pressure to be exerted on the valve sleeve. The differential pressure exerted on the valve sleeve may be the result of an upstream pressure and a downstream pressure. By allowing a differential pressure resulting from a fluid flow to act on the valve sleeve, u-tubing in a drill string can be prevented or substantially reduced. Methods of use are also provided.

1. A drill string flow control valve comprising:
 a valve housing characterized by a wall defining a valve interior, wherein the valve housing has an internal housing flow path formed therein with a housing outlet flow port disposed along said internal housing flow path; 
 a valve sleeve disposed at least partially in the interior of the valve housing, the valve sleeve having a sleeve flow port and a valve sleeve wall, wherein the valve sleeve is axially movable within the valve housing from a closed position to an open position, such that the valve sleeve wall substantially impedes fluid flow from the housing outlet flow port to the sleeve flow port when the valve sleeve is in the closed position and wherein the sleeve flow port and the housing outlet flow port are in substantial alignment when in the open position; 
 wherein the valve sleeve has an upper pressure surface defined thereon so as to provide a first surface area upon which a first fluid pressure from the internal housing flow path may act to provide a downward force on the valve sleeve and wherein the valve sleeve has a lower pressure surface defined thereon so as to provide a second surface area upon which a second fluid pressure may act to provide an upward force on the valve sleeve; 
 a spring wherein the spring biases the valve sleeve to the closed position by exertion of a biasing force on the valve sleeve; 
 an upper pressure port split off from said internal housing flow path, said upper pressure port disposed to allow the first fluid pressure to act upon the upper pressure surface; and 
 a lower pressure port that allows the second fluid pressure to act upon the lower pressure surface from external the valve housing. 
 
   
   
     2. The drill string flow control valve of  claim 1  wherein the valve sleeve is capable of axially shifting from the closed position to the open position by a sufficient differential fluid pressure exerted on the valve sleeve so as to overcome the biasing force of the spring. 
   
   
     3. The drill string flow control valve of  claim 1  wherein the drill string flow control valve is axially disposed within a drill string. 
   
   
     4. The drill string flow control valve of  claim 1  wherein the drill string flow control valve forms an inline member of a drill string wherein the drill string flow control valve has threaded end connections for attaching to one or more joints of drill pipe. 
   
   
     5. The drill string flow control valve of  claim 1  wherein the upper pressure port is axially formed in the housing. 
   
   
     6. The drill string flow control valve of  claim 1  further comprising an adjustment shim to allow for adjustment of a tension of the spring. 
   
   
     7. The drill string flow control valve of  claim 1  wherein the spring has a spring constant sufficient to prevent u-tubing of fluid flow upon termination of a pumping force. 
   
   
     8. The drill string flow control valve of  claim 1  wherein the upper pressure surface and the lower pressure surface comprise an extension protruding from the valve sleeve. 
   
   
     9. The drill string flow control valve of  claim 1  wherein the lower pressure surface is an extension protruding from the valve sleeve. 
   
   
     10. The drill string flow control valve of  claim 1  wherein the upper pressure surface comprises an extension protruding from the valve sleeve. 
   
   
     11. The drill string flow control valve of  claim 1  wherein the spring acts upon the lower pressure surface to produce the biasing force on the valve sleeve. 
   
   
     12. A drill string flow control valve comprising:
 a valve housing characterized by a wall defining a valve interior, wherein the valve housing has an internal housing flow path channel formed therein with a housing outlet flow port disposed along said flow path channel; 
 a valve sleeve disposed at least partially in the valve housing, the valve sleeve having a sleeve flow port and a valve sleeve wall, wherein the valve sleeve is axially movable within the valve housing from a closed position to an open position, such that the valve sleeve wall substantially impedes fluid flow from the housing outlet flow port to the sleeve flow port when the valve sleeve is in the closed position and wherein the sleeve flow port and the housing outlet flow port are substantially aligned when in the open position; 
 wherein the valve sleeve has a first pressure surface defined thereon so as to provide a first surface area upon which a first fluid pressure from the internal housing flow path channel may act to provide a downward force on the valve sleeve and wherein the valve sleeve has a second pressure surface defined thereon so as to provide a second surface area upon which a second fluid pressure may act to provide an upward force on the valve sleeve; 
 a biasing mechanism wherein the biasing mechanism biases the valve sleeve to the closed position; 
 a first pressure channel split off from said internal housing flow path channel, said first pressure channel disposed to allow the first fluid pressure to act upon the first pressure surface; and 
 a second pressure channel that allows the second fluid pressure to act upon the second pressure surface from external the valve housing. 
 
   
   
     13. The drill string flow control valve of  claim 12  wherein the biasing mechanism comprises a spring. 
   
   
     14. The drill string flow control valve of  claim 13  wherein the spring comprises a coil spring. 
   
   
     15. A method for preventing u-tubing in a drill string comprising:
 providing a valve housing wherein the valve housing has an internal housing flow path defined therein with a housing outlet flow port disposed along said flow path; 
 providing a valve sleeve disposed at least partially in the valve housing, the valve sleeve having a sleeve flow port and a valve sleeve wall, wherein the valve sleeve is axially movable within the valve housing from a closed position to an open position, such that the valve sleeve wall substantially impedes fluid flow from the housing outlet flow port to the sleeve flow port when the valve sleeve is in the closed position and wherein the sleeve flow port and the housing outlet flow port are substantially aligned when in the open position, wherein the valve sleeve has an upper pressure surface defined thereon so as to provide a first surface area upon which a first fluid pressure from the internal housing flow path may act to provide a downward force on the valve sleeve and wherein the valve sleeve has a lower pressure surface defined thereon so as to provide a second surface area upon which a second fluid pressure may act to provide an upward force on the valve sleeve; 
 providing a biasing mechanism wherein the biasing mechanism biases the valve sleeve to the closed position by exerting a biasing spring force on the valve sleeve; 
 providing an upper pressure port split off from said internal housing flow path, said upper pressure port disposed to allow the first fluid pressure to act upon the upper pressure surface with a first force; 
 providing a lower pressure port that allows the second fluid pressure to act upon the lower pressure surface from external the valve housing with a second force; 
 introducing drilling fluid into the valve to create a fluid pressure applied to the valve sleeve; 
 increasing the fluid pressure upon the valve sleeve so as to cause the valve sleeve to shift from the closed position to the open position; 
 maintaining a drilling fluid flow through the valve sleeve so that the first force is greater than the biasing spring force plus the second force; and 
 decreasing the fluid flow through the valve sleeve so as to allow the biasing mechanism to shift the valve sleeve from the open position to the closed position. 
 
   
   
     16. The method of  claim 15  wherein the biasing mechanism comprises a coiled spring. 
   
   
     17. A drill string flow control valve system comprising:
 a valve housing wherein the valve housing has an internal housing flow path formed therein and a housing outlet flow port disposed along said internal housing flow path; 
 a valve sleeve disposed at least partially in the valve housing, the valve sleeve having a sleeve flow port and a valve sleeve wall wherein the valve sleeve is axially movable within the valve housing from a closed position to an open position, such that the valve sleeve wall substantially impedes fluid flow from the housing outlet flow port to the sleeve flow port when the valve sleeve is in the closed position and wherein the sleeve flow port and the housing outlet flow port are substantially aligned when in the open position; 
 wherein the valve sleeve has an upper pressure surface defined thereon so as to provide a first surface area upon which a first fluid pressure from the internal housing flow path may act to provide a downward force on the valve sleeve and wherein the valve sleeve has a lower pressure surface defined thereon so as to provide a second surface area upon which a second fluid pressure may act to provide an upward force on the valve sleeve; 
 a biasing mechanism wherein the spring biases the valve sleeve to the closed position by exertion of a biasing force on the valve sleeve; 
 a flow restriction in fluid communication with the valve sleeve; 
 an upper pressure port split off from said internal housing flow path and upstream of the flow restriction, said upper pressure port disposed to allow the first fluid pressure to act upon the upper pressure surface, wherein the first fluid pressure is measured upstream of the flow restriction; and 
 a lower pressure port that allows the second fluid pressure to act upon the lower pressure surface from external the valve housing, wherein the second fluid pressure is measured downstream of the flow restriction. 
 
   
   
     18. The method of  claim 17  wherein the biasing mechanism comprises a spring. 
   
   
     19. The method of  claim 17  wherein the flow restriction is disposed inside the valve sleeve. 
   
   
     20. A drill string flow control valve system comprising:
 a valve housing having an external surface and a first flow path internally disposed therein; 
 a valve sleeve slidingly mounted in the valve housing; 
 a biasing mechanism for biasing the valve sleeve in a closed position; 
 a first pressure port split off from said internally disposed first flow path, said first pressure port in fluid communication with a first surface of the sleeve to provide a pressure acting on the first surface of the sleeve; 
 a second pressure port in fluid communication with a second surface of the sleeve to provide a pressure acting on the second surface of the sleeve, said second pressure port in fluid communication with a second flow path; and 
 a drill string having an internal annulus therein, wherein said drill string is disposed in a wellbore, and wherein the first pressure port is in fluid communication with said internal annulus and said second pressure port is in fluid communication with said wellbore. 
 
   
   
     21. A drill string flow control valve comprising:
 a valve housing wherein the valve housing has an internal housing flow path with a housing outlet flow port disposed along said flow path; 
 a valve sleeve disposed at least partially in the valve housing, the valve sleeve having a sleeve flow port and a valve sleeve wall wherein the valve sleeve is axially movable within the valve housing from a closed position to an open position, such that the valve sleeve wall substantially impedes fluid flow from the housing outlet flow port to the sleeve flow port when the valve sleeve is in the closed position and wherein the sleeve flow port and the housing outlet flow port are substantially aligned when in the open position; 
 wherein the valve sleeve has an upper pressure surface defined thereon so as to provide a first surface area upon which a first fluid pressure from the housing flow path may act to provide a downward force on the valve sleeve and wherein the valve sleeve has a lower pressure surface defined thereon so as to provide a second surface area upon which a second fluid pressure may act to provide an upward force on the valve sleeve; 
 a spring wherein the spring biases the valve sleeve to the closed position by exertion of a biasing force on the valve sleeve; 
 an upper pressure port that allows the first fluid pressure to act upon the upper pressure surface; 
 a lower pressure port that allows the second fluid pressure to act upon the lower pressure surface from within the valve sleeve; and 
 a restriction in the valve sleeve between upper pressure port and the lower pressure port, said valve sleeve having a first inner diameter substantially along its length and said restriction characterized by a second inner diameter smaller than the first inner diameter.